Add programmatic tab renaming (#744)

* Fix announcement link

* Added name property to Tab interface

Author: BrunoScheufler

packages/graphql-playground-react/src/state/sessions/reducers.ts

@@ -37,6 +37,7 @@ export interface SessionStateProps {
 export interface Tab {
   endpoint: string
   query: string
+  name?: string
   variables?: string
   responses?: string[]
   headers?: { [key: string]: string }